package lab02.test36;

/**
 * 研究生
 *
 */
public class Postgraduate extends Student {

    @Override
    String calGrade() {
 //成绩等级
        String grade="";

        double avg=average();

        if (avg>=90&&avg<=100)
            grade="优秀";
        else if (avg>=80&&avg<90)
            grade="良好";
        else if (avg>=70&&avg<80)
            grade="一般";
        else if (avg<70&&avg>=60)
            grade="及格";
        else
            grade="不及格";

        return grade;
    }
}
